Статті в журналах з теми "Lateral building separation"
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1
Filiatrault, André, and Mario Cervantes. "Separation between buildings to avoid pounding during earthquakes." Canadian Journal of Civil Engineering 22, no. 1 (February 1, 1995): 164–79. http://dx.doi.org/10.1139/l95-015.
Анотація:
This paper presents an analytical investigation on the required separations between adjacent buildings to avoid pounding during earthquakes. Five wall buildings, having 3, 6, 10, 15, and 25 storeys, were designed for three different seismic zones in Canada: Montreal, Vancouver, and Prince Rupert. For each zone, an ensemble of code compatible ground motions was identified. Nonlinear time-step dynamic analyses were performed to determine the separations to avoid pounding between each building pair under each earthquake. The required separations, obtained by subtracting the time-histories of lateral displacements between adjacent floor levels, were compared with the requirements of the static method of the National Building Code of Canada. The results indicate that the static method of the code grossly overestimates the required separations. This is to be expected, since the static code procedure does not take full account of the intervening variables (periods, responses, and phases between building motions) which characterize the ground motion and building properties when determining the separation distances. A simplified spectral difference procedure is proposed for inclusion in future editions of the code. Key words: dynamics, earthquake, gap, pounding, seismic, separations.
2
Rios Mora, Juan Sebastian, Bernard Collignan, Thierno Diallo, Marc Abadie, and Karim Limam. "Influence of the lateral source/building separation on vapour intrusion: A numerical study." E3S Web of Conferences 172 (2020): 07006. http://dx.doi.org/10.1051/e3sconf/202017207006.
Анотація:
Various vapour intrusion (VI) models have been proposed in order to predict indoor concentration of Volatile Organic Compounds (VOCs) in buildings. However, these models tend to be conservative, and overestimate or underestimate vapour flux emissions due to several assumptions. Particularly, most of these VI models only consider an infinite uniform contaminated groundwater as the principal source of VOCs in the soil, and lateral pollution source in the vadose zone are disregarded. It has been shown that ignoring the lateral source position may lead to uncertainties on the estimations. In this paper, a numerical model is developed in order to better understand the relationship between the lateral source position in the soil, including both a source in the vadose zone and a source located at the groundwater level, and the resulting indoor air concentration. Results show that source position plays a significant role on vapour intrusion attenuation. In fact, indoor concentration of VOCs decreases with increasing lateral separation. Finally, it is shown that considering the source position can significantly improve the quality of VI predictions.
3
Masmoum, M. S., and M. S. A. Alama. "Required Separation to Mitigate Pounding of Adjacent Building Blocks." Engineering, Technology & Applied Science Research 8, no. 6 (December 22, 2018): 3565–69. http://dx.doi.org/10.48084/etasr.2386.
Анотація:
This research discusses the feasibility of using the required minimum separation distance based on SBC 301-2007. Moment resistance frames were designed with expansion joints requiring 400mm separation distance. Nonlinear response history analysis was conducted with four ground motions selected and scaled to match the risk-targeted response spectrum of NEOM city based on ASCE 7-16 provisions. An equivalent spring constant value based on floor lateral stiffness was selected as a gap link stiffness. Finally, an evaluation for the pounding response of adjacent blocks is presented along with the conclusions.
4
Yao, Yijun, Rui Shen, Kelly G. Pennell, and Eric M. Suuberg. "Estimation of Contaminant Subslab Concentration in Vapor Intrusion Including Lateral Source-Building Separation." Vadose Zone Journal 12, no. 3 (July 26, 2013): vzj2012.0157. http://dx.doi.org/10.2136/vzj2012.0157.
5
Verginelli, Iason, Oriana Capobianco, and Renato Baciocchi. "Role of the source to building lateral separation distance in petroleum vapor intrusion." Journal of Contaminant Hydrology 189 (June 2016): 58–67. http://dx.doi.org/10.1016/j.jconhyd.2016.03.009.
6
Awchat, Ganesh Deoraoji, Amruta Monde, Rajat Sirsikar, Rahul Dingane, and Gopal Dhanjode. "Seismic Pounding Response of Neighboring Structure using Various Codes with Soil-Structure Interaction effects: Focus on Separation Gap." Civil Engineering Journal 8, no. 2 (February 1, 2022): 308–18. http://dx.doi.org/10.28991/cej-2022-08-02-09.
Анотація:
Due to the high cost and less availability of land, the buildings are constructed adjacent to each other with a significantly smaller separation gap. Whenever seismic forces act on adjacent structures, they collide and cause significant structural and architectural damage. Soil-Structure Interaction (SSI) effects cause more complications in the adjacent structures. This paper assesses the gap distance between RC bare frame adjacent structures of varying heights in medium and soft soil with and without SSI to avoid the pounding effect of an earthquake. The main objectives are to find the separation distance between adjacent buildings by the provisions of FEMA 356, IS 1893 (Part 1):2002, IS 1893 (Part 1):2016 and EN 1998-1:2004. The separation gap between different codes was then compared to determine the minimum separation required to prevent pounding between the structures. The maximum lateral displacement on the roof and the time period of the adjacent buildings are compared with and without SSI. There is a significant increase in lateral displacement, separation distance, and time period considering SSI. It is found that the Indian code overestimates the separation distance. Thus, this study guides structural engineers to maintain a minimum separation distance between buildings erected on medium and soft soils in high seismic zones of India. Doi: 10.28991/CEJ-2022-08-02-09 Full Text: PDF
7
Rahgozar, Peyman. "Free Vibration of Tall Buildings using Energy Method and Hamilton’s Principle." Civil Engineering Journal 6, no. 5 (May 1, 2020): 945–53. http://dx.doi.org/10.28991/cej-2020-03091519.
Анотація:
In a framed-tube tall building, shear wall systems are the most efficient structural systems for increasing the lateral load resistance. A novel and simple mathematical model is developed herein which calculates the natural frequencies of such tall buildings. The analyses are based on a continuous model, in which a tall building structure is replaced by an idealized cantilever beam that embodies all relevant structural characteristics. Governing equations and the corresponding eigen-problem are derived based on the energy method and Hamilton’s principle. Solutions are obtained for three examples; using the separation of variables technique implemented in MATLAB. The results are compared to SAP2000 full model analysis; and they indicate reasonable accuracy. The computed natural frequencies for structures 50, 60 and 70 storey buildings were over-estimate 7, 11 and 14 percent respectively. The computed errors indicate that the proposed method has acceptable accuracy; and can be used during the initial stages of designing of tall buildings; it is fast and low cost computational process.
8
Khatami, Seyed Mohammad, Hosein Naderpour, Seyed Mohammad Nazem Razavi, Rui Carneiro Barros, Anna Jakubczyk-Gałczyńska, and Robert Jankowski. "Study on Methods to Control Interstory Deflections." Geosciences 10, no. 2 (February 18, 2020): 75. http://dx.doi.org/10.3390/geosciences10020075.
Анотація:
One of the possibilities to prevent building pounding between two adjacent structures is to consider appropriate in-between separation distance. Another approach might be focused on controlling the relative displacements during seismic excitations. Although the majority of building codes around the world recommend the use of some equations of various distances between structures to avoid pounding; a lot of reports after earthquakes have obviously shown that safety situation or economic consideration is not always provided due to the collisions between buildings and high cost of land; respectively. The aim of the present paper is to focus the analysis on the properties of structures and conduct an in-depth analysis of available methods to control interstory deflections so as to prevent pounding. For this purpose, a numerical lumped mass model of the five-story building has been considered and its response under different earthquake records has been investigated. Firstly, the influence of the change in structural properties (story stiffness; mass and damping) has been examined. Then the application of tuned mass damper, base isolation and base isolation with rubber bumpers has been considered. The results of comparative analyses clearly indicate that using base isolation, with the addition of bumpers, can be selected as the best method to control building deflections and decrease absolute lateral displacement between two buildings so as to prevent their pounding during earthquakes
9
Soloviov, Dmytro, Yong Q. Cai, Dima Bolmatov, Alexey Suvorov, Kirill Zhernenkov, Dmitry Zav’yalov, Alexey Bosak, Hiroshi Uchiyama, and Mikhail Zhernenkov. "Functional lipid pairs as building blocks of phase-separated membranes." Proceedings of the National Academy of Sciences 117, no. 9 (February 18, 2020): 4749–57. http://dx.doi.org/10.1073/pnas.1919264117.
Анотація:
Biological membranes exhibit a great deal of compositional and phase heterogeneity due to hundreds of chemically distinct components. As a result, phase separation processes in cell membranes are extremely difficult to study, especially at the molecular level. It is currently believed that the lateral membrane heterogeneity and the formation of domains, or rafts, are driven by lipid–lipid and lipid–protein interactions. Nevertheless, the underlying mechanisms regulating membrane heterogeneity remain poorly understood. In the present work, we combine inelastic X-ray scattering with molecular dynamics simulations to provide direct evidence for the existence of strongly coupled transient lipid pairs. These lipid pairs manifest themselves experimentally through optical vibrational (a.k.a. phononic) modes observed in binary (1,2-dipalmitoyl-sn-glycero-3-phosphocholine [DPPC]–cholesterol) and ternary (DPPC–1,2-dioleoyl-sn-glycero-3-phosphocholine/1-palmitoyl-2-oleoyl-glycero-3-phosphocholine [DOPC/POPC]–cholesterol) systems. The existence of a phononic gap in these vibrational modes is a direct result of the finite size of patches formed by these lipid pairs. The observation of lipid pairs provides a spatial (subnanometer) and temporal (subnanosecond) window into the lipid–lipid interactions in complex mixtures of saturated/unsaturated lipids and cholesterol. Our findings represent a step toward understanding the lateral organization and dynamics of membrane domains using a well-validated probe with a high spatial and temporal resolution.
10
El-Sisi, Alaa A., Mohammed M. Elgiar, Hassan M. Maaly, Osman A. Shallan, and Hani A. Salim. "Effect of Welding Separation Characteristics on the Cyclic Behavior of Steel Plate Shear Walls." Buildings 12, no. 7 (June 22, 2022): 879. http://dx.doi.org/10.3390/buildings12070879.
Анотація:
Currently, the steel plate shear wall (SPSW) is commonly used in high-rise steel buildings as a lateral load-resisting system due to its several advantages such as its lightweight and high ductility and strength. The SPSW consists of two main parts, i.e., the boundary frame and infill plate, which are connected by welding. The objective of this work is to study the effect of the infill plate weld separation on the seismic behavior of the SPSWs. A numerical method was proposed to have a comprehensive comparison of seismic behaviors of different separation characteristics. The model was validated by using previously published experimental works. Key parameters, such as load-carrying capacity, stiffness, and energy-dissipation capacity, were discussed extensively. The unstiffened SPSW (USPSW) system is more sensitive to the plate–beam separation than the plate–column one, especially the corner plate–beam separation. When plate–column welding separation occurs, the initial stiffness and the energy dissipation capacity are reduced by approximately 21% and 14%, respectively; however, the reductions are 36% and 20.5% in the case of beam welding separation.
11
Florenţa, Ion, Nicolae Ţăranu, Alexandru Secu, Ana Raluca Roşu, and Dragoş Ungureanu. "Analytical Procedures for Calculation of Horizontal Displacement of Timber Shear Walls." Advanced Engineering Forum 21 (March 2017): 135–40. http://dx.doi.org/10.4028/www.scientific.net/aef.21.135.
Анотація:
The shear wall horizontal displacement is one of the most important parameters involved in the seismic design of the timber framed structures. This paper presents the fundamentals of displacement-based seismic design, along with a description of the requirements for its application: checking of the maximum allowable displacement, checking of the buildings’ separation and determining the stiffness of the walls. The horizontal displacement of a shear wall is determined through the analytical calculation of the wall elements’ displacements. For timber framed structure, the International Building Code (IBC), recommends analytical models for the determination of the horizontal displacement. However, the European norm, Eurocode 5 does not provide any calculation model for the lateral displacement. A comparative study of the available analytical models and the corresponding results are presented in this paper.
12
Kazemi, F., M. Miari, and R. Jankowski. "Investigating the effects of structural pounding on the seismic performance of adjacent RC and steel MRFs." Bulletin of Earthquake Engineering 19, no. 1 (November 6, 2020): 317–43. http://dx.doi.org/10.1007/s10518-020-00985-y.
Анотація:
AbstractAn insufficient separation distance between adjacent buildings is the main reason for structural pounding during severe earthquakes. The lateral load resistance system, fundamental natural period, mass, and stiffness are important factors having the influence on collisions between two adjacent structures. In this study, 3-, 5- and 9-story adjacent reinforced concrete and steel moment resisting frames (MRFs) were considered to investigate the collision effects and to determine modification factors for new and already existing buildings. For this purpose, incremental dynamic analysis was used to assess the seismic limit state capacity of the structures using a developed algorithm in OpenSees software including two near-field record subsets suggested by FEMA-P695. The results of this paper can help engineers to approximately estimate the performance levels of MRFs due to pounding phenomenon. The results confirm that collisions can lead to the changes in performance levels, which are difficult to be considered during the design process. In addition, the results of the analyses illustrate that providing a fluid viscous damper between adjacent reinforced concrete and steel structures can be effective to eliminate the sudden changes in the lateral force during collision. This approach can be successfully used for retrofitting adjacent structures with insufficient in-between separation distances.
13
Li, Xue Ling, Xiang Chao Yin, and Hai Bin Zhang. "Seismic Response Analysis of Different Plane Structure in Horizontal Direction." Applied Mechanics and Materials 90-93 (September 2011): 2487–91. http://dx.doi.org/10.4028/www.scientific.net/amm.90-93.2487.
Анотація:
The results of theoretical research and earthquake damage investigation show that seismic response analysis of different plane structure in horizontal direction is different. Dynamic characteristics and seismic response analysis of four kinds of architectural models with different planes were analyzed by using the finite element analysis software. The inherent characteristics and earthquake time-history curves in different intensity level X, Y direction of displacement, velocity, acceleration and angle displace were studied. The results show that the seismic response of the four kinds of structures separates gradually, and the separation gap increases with increase of earthquake intensity. The building structure is safer in the long side direction than that in the short side in lateral earthquake response. The irregular structure can cause strong response in both horizontal in a single direction of earthquake effect. The second floor is a weak layer of the building structure which should be paid more attention to.
14
Guo, Dong-Peng, Peng Zhao, Ren-Tai Yao, Yun-Peng Li, Ji-Min Hu, and Dan Fan. "Numerical and Wind Tunnel Simulation Studies of the Flow Field and Pollutant Diffusion around a Building under Neutral and Stable Atmospheric Stratifications." Journal of Applied Meteorology and Climatology 58, no. 11 (November 2019): 2405–20. http://dx.doi.org/10.1175/jamc-d-19-0045.1.
Анотація:
AbstractIn this paper, the k–ε renormalization group (RNG) turbulence model is used to simulate the flow and dispersion of pollutants emitted from a source at the top of a cubic building under neutral and stable atmospheric stratifications, the results of which were compared with corresponding wind tunnel experiment results. When atmosphere stratification is stable, the separation zones on the sides and at the top of a building are relatively smaller than those under neutral conditions, and the effect of the building in the horizontal direction is stronger than that in the vertical direction. The variation in turbulent kinetic energy under stable conditions is significantly lower than that under neutral conditions. The effect of atmospheric stratification on the turbulent kinetic energy becomes gradually more prominent with increased distance. When atmosphere conditions are stable, the vertical distribution of the plume is smaller than that of neutral conditions, but the lateral spread and near-ground concentration are slightly larger than those of neutral conditions, mainly because stable atmospheric stratification suppresses the vertical motions of airflow and increases the horizontal spread of the plume.
15
Fu, Peng, and Kanghe Xie. "Lateral Vibration of Offshore Piles Considering Pile-Water Interaction." International Journal of Structural Stability and Dynamics 19, no. 12 (December 2019): 1950147. http://dx.doi.org/10.1142/s0219455419501475.
Анотація:
The dynamic response of an offshore pile in saturated soil subjected to lateral harmonic loading is theoretically investigated by considering the dynamic pile-water interaction. The governing equation of water is solved based on the separation of variable method, and the analytical expression of the hydrodynamic force applied on the pile is then obtained. Based on the continuous conditions at the pile-soil interface and pile-water interface, the analytical solution of the dynamic impedance of the offshore pile is derived by using transfer matrix method. To verify this solution, the dynamic impedance obtained for a cylinder in water is compared with that of a partially embedded pile. Based on this solution, the effect of hydrodynamic pressure and other parameters on the dynamic response of offshore piles is investigated. The results show that the analytical model ignoring the hydrodynamic force applied on the pile misestimates the impedance of the pile in the high frequency range.
16
Pietra, Dario, Stefano Pampanin, Ron L. Mayes, Nicholas G. Wetzel, and Demin Feng. "Design of base-isolated buildings." Bulletin of the New Zealand Society for Earthquake Engineering 48, no. 2 (June 30, 2015): 118–35. http://dx.doi.org/10.5459/bnzsee.48.2.118-135.
Анотація:
Base isolation is arguably the most reliable method for providing enhanced protection of buildings against earthquake-induced actions, by virtue of a physical separation between the structure and the ground through elements/devices with controlled force capacity, significant lateral deformation capacity and (often) enhanced energy dissipation. Such a design solution has shown its effectiveness in protecting both structural and non-structural components, hence preserving their functionality even in the aftermath of a major seismic event.
Despite lead rubber bearings being invented in New Zealand almost forty years ago, the Christchurch Women’s hospital was the only isolated building in Christchurch when the Canterbury earthquake sequence struck in 2010/11. Furthermore, a reference code for designing base-isolated buildings in New Zealand is still missing. The absence of a design standard or at least of a consensus on design guidelines is a potential source for a lack of uniformity in terms of performance criteria and compliance design approaches. It may also limit more widespread use of the technology in New Zealand.
The present paper provides an overview of the major international codes (American, Japanese and European) for the design of base-isolated buildings. The design performance requirements, the analysis procedures, the design review process and approval/quality control of devices outlined in each code are discussed and their respective pros and cons are compared through a design application on a benchmark building in New Zealand. The results gathered from this comparison are intended to set the basis for the development of guidelines specific for the New Zealand environment.
17
Wang, Genfu, Yuting Xiao, Jianping Zuo, Yue Wang, Jun Man, Wei Tang, Qiang Chen, Shuaishuai Ma, and Yijun Yao. "Physically simulating the effect of lateral vapor source-building separation on soil vapor intrusion: Influences of surface pavements and soil heterogeneity." Journal of Contaminant Hydrology 235 (November 2020): 103712. http://dx.doi.org/10.1016/j.jconhyd.2020.103712.
18
Khatami, Seyed Mohammad, Hosein Naderpour, Alireza Mortezaei, Alireza Sharbatdar, Natalia Lasowicz, and Robert Jankowski. "The Effectiveness of Rubber Bumpers in Reducing the Effects of Earthquake-Induced Pounding between Base-Isolated Buildings." Applied Sciences 12, no. 10 (May 14, 2022): 4971. http://dx.doi.org/10.3390/app12104971.
Анотація:
The methods for preventing earthquake-induced structural pounding between two adjacent buildings include ensuring a sufficient separation distance between them or decreasing their relative displacement during seismic excitation. Some equations or even specific values of such gap sizes between two buildings have been introduced so as to avoid collisions. Increasing the stiffness of buildings, using tuned mass dampers, applying liquid dampers, or decreasing the mass of the structures may reduce lateral displacements, and therefore pounding can be prevented. On the other hand, the application of base isolation systems may result in the elongation of the natural period of the building, thus increasing the probability of structural pounding. The aim of the present paper is to verify the effectiveness of using rubber bumpers to reduce the negative effects of earthquake-induced pounding between base-isolated buildings. The analysis was conducted for different gap sizes between buildings, as well as for various values of the thickness, number and stiffness of rubber bumpers. The results of the study show that the peak impact force decreases with increasing thickness, stiffness, and number of bumpers. Moreover, the peak impact forces are reduced with increasing gap size. The results of the investigation clearly indicate that the use of additional rubber bumpers can be considered an effective method for reducing the negative effects of earthquake-induced pounding between base-isolated buildings.
19
DeVall, Ronald H. "Background information for some of the proposed earthquake design provisions for the 2005 edition of the National Building Code of Canada." Canadian Journal of Civil Engineering 30, no. 2 (April 1, 2003): 279–86. http://dx.doi.org/10.1139/l02-048.
Анотація:
There are many changes proposed for the Earthquake Design Provisions of the 2005 edition of the National Building Code of Canada (NBCC). Among them are requirements for complete load paths, separation of stiff nonstructural elements, and the introduction of definitions of irregular structures and special design requirements associated with these irregularities. A new requirement for direction of loading is introduced, along with requirements for elements common to more than one lateral load resisting system. The effects of displacements are emphasized throughout the document, and revised provisions for drift limits are proposed. Revisions to the importance factor that integrate it into the proposed revised format for Part 4, Structural design, of the NBCC are given. Background information is presented.Key words: load path importance factor, irregular structures, direction of loading, special requirements, drift limits.
20
Hyland, Clark W. K., and Sugeng Wijanto. "Lessons for steel structures from the 2009 earthquake damage in Padang." Bulletin of the New Zealand Society for Earthquake Engineering 43, no. 2 (June 30, 2010): 134–39. http://dx.doi.org/10.5459/bnzsee.43.2.134-139.
Анотація:
The Padang earthquake is a timely reminder to New Zealand structural engineers of a number of things with respect to seismic design and construction practice of steel structures. These include: The importance of implementing the latest seismic loadings and design technology into new and existing structures without undue delay; The need to maintain an effective Building Code enforcement and audit process, including the keeping of publicly transparent compliance records; The important role of the design engineer in observing and auditing the interpretation and implementation of the design is essential, to prevent improper substitution of materials and ill-considered design changes; The need for ongoing continuing professional development and education for design, construction and building code enforcement officials to develop and maintain technical competency; The separation of non-structural elements from interfering with the primary seismic resisting system needs to be carried through diligently from design and into construction. Where structural separation is not achieved then design models for integrating unreinforced brickwork panels within moment resisting frames need to be developed, particularly for retrofit situations; The design for weak-axis bending of two way moment resisting steel frames requires careful attention to secondary effects, and should be avoided where possible; Non-self centring structural elements need to be identified at design stage and designed to minimise inelastic behaviour during ultimate limit state earthquakes; Diagonal bracing rods should be designed to avoid failure within couplings. Consideration should also be given to the dynamic response of the roof level bracing system to heavy wall induced lateral loads; Connections at the interface of steel work with concrete and masonry sub-trades need to be carefully monitored to ensure intended design performance is achieved; Unreinforced masonry without lateral tiebacks should be avoided on lintels over egress-ways; A guide of typical structural repair methods would also be a useful tool for post-earthquake use, to quickly identify appropriate repair strategies and allow repair estimates to be developed. At a philosophical level, should a post-earthquake repair be required to simply allow a resumption of functionality? Alternatively should the repair be required to reinstate the structural performance to its pre-earthquake strength? Or should the repair improve the seismic resisting performance of the structure in line with current earthquake engineering knowledge?
21
Wang, Haiyang, Satish C. Singh, Francois Audebert, and Henri Calandra. "Inversion of seismic refraction and reflection data for building long-wavelength velocity models." GEOPHYSICS 80, no. 2 (March 1, 2015): R81—R93. http://dx.doi.org/10.1190/geo2014-0174.1.
Анотація:
Long-wavelength velocity model building is a nonlinear process. It has traditionally been achieved without appealing to wave-equation-based approaches for combined refracted and reflected waves. We developed a cascaded wave-equation tomography method in the data domain, taking advantage of the information contained in the reflected and refracted waves. The objective function was the traveltime residual that maximized the crosscorrelation function between real and synthetic data. To alleviate the nonlinearity of the inversion problem, refracted waves were initially used to provide vertical constraints on the velocity model, and reflected waves were then included to provide lateral constraints. The use of reflected waves required scale separation. We separated the long- and short-wavelength subsurface structures into velocity and density models, respectively. The velocity model update was restricted to long wavelengths during the wave-equation tomography, whereas the density model was used to absorb all the short-wavelength impedance contrasts. To improve the computation efficiency, the density model was converted into the zero-offset traveltime domain, where it was invariant to changes of the long-wavelength velocity model. After the wave-equation tomography has derived an optimized long-wavelength velocity model, full-waveform inversion was used to invert all the data to retrieve the short-wavelength velocity structures. We developed our method in two synthetic tests and then applied it to a marine field data set. We evaluated the results of the use of refracted and reflected waves, which was critical for accurately building the long-wavelength velocity model. We showed that our wave-equation tomography strategy was robust for the real data application.
22
Trikhunkov, Ya I., D. М. Bachmanov, О. V. Gaydalenok, А. V. Marinin, and S. А. Sokolov. "Recent mountain-building at the boundary juction of the North-Western Caucasus and intermediate Kerch-Taman Region, Russia." Геотектоника, no. 4 (August 13, 2019): 78–96. http://dx.doi.org/10.31857/s0016-853x2019378-96.
Анотація:
In this paper the recent evolution of marginal segment of the North-Western Caucasus orogen in its junction to Kerch-Taman periclinal trough was studied. Geomorphological analysis included geological, tectonophysics data and digital elevation models was carried out. The North-Western Caucasus torn-folded morphostructures that had their extension in intermediate Kerch-Taman region westward to North-Western Caucasus mountain structure are both established to be developed in uniform regional compression settings. The prevailing horizontal compression direction changed from N–E in the North-Western Caucasus to the meridional one in Taman region, which was expressed in the reorientation of the axes of the folded morphostructures and geophysical anomalies from N–W to the latitudinal direction. The separation of the compressional vectors occurred in Pliocene-Quaternary period. Pre-Pliocene fault structures of N–E strike in this area were replaced with meridional Anapa-Dzhiginka and Abrau active fault zones.We compared Abrau zone with Anapa-Dzhiginka zone and established the faulting in Abrau zone became more dynamic in Pliocene-Quaternary stage, we revealed clear signs of vertical amplitude droppable-sliding kinematics of 500–600 m of normal fault deformation in Abrau zone during this stage. Abrau zone is the Greater Caucasus western boundary zone.The possible reasons for the restructuring of regional structural geometry and lateral transition activity of the faults transverse to the Northern-Western Caucasus orogen, are considered.
23
Dias Louro, Marco António, Mónica Bettencourt-Dias, and Jorge Carneiro. "A first-takes-all model of centriole copy number control based on cartwheel elongation." PLOS Computational Biology 17, no. 5 (May 10, 2021): e1008359. http://dx.doi.org/10.1371/journal.pcbi.1008359.
Анотація:
How cells control the numbers of its subcellular components is a fundamental question in biology. Given that biosynthetic processes are fundamentally stochastic it is utterly puzzling that some structures display no copy number variation within a cell population. Centriole biogenesis, with each centriole being duplicated once and only once per cell cycle, stands out due to its remarkable fidelity. This is a highly controlled process, which depends on low-abundance rate-limiting factors. How can exactly one centriole copy be produced given the variation in the concentration of these key factors? Hitherto, tentative explanations of this control evoked lateral inhibition- or phase separation-like mechanisms emerging from the dynamics of these rate-limiting factors but how strict centriole number is regulated remains unsolved. Here, a novel solution to centriole copy number control is proposed based on the assembly of a centriolar scaffold, the cartwheel. We assume that cartwheel building blocks accumulate around the mother centriole at supercritical concentrations, sufficient to assemble one or more cartwheels. Our key postulate is that once the first cartwheel is formed it continues to elongate by stacking the intermediate building blocks that would otherwise form supernumerary cartwheels. Using stochastic models and simulations, we show that this mechanism may ensure formation of one and only one cartwheel robustly over a wide range of parameter values. By comparison to alternative models, we conclude that the distinctive signatures of this novel mechanism are an increasing assembly time with cartwheel numbers and the translation of stochasticity in building block concentrations into variation in cartwheel numbers or length.
24
Bawallah, Musa Adesola, Stephen Olubusola Ilugbo, Kesyton Oyamenda Ozegin, Babatunde A. Adebo, Isaac Aigbedion, and Kazeem Adeyinka Salako. "Electrical Resistivity and Geotechnical Attributes and The Dynamics of Foundation Vulnerability." Indonesian Journal of Earth Sciences 1, no. 2 (December 17, 2021): 84–97. http://dx.doi.org/10.52562/injoes.v1i2.253.
Анотація:
This research evaluates the significance of geotechnical and Electrical Resistivity methods in studying structural integrity as fundamental factors that may account for failure in a typical sedimentary environment of Ukpenu Primary School, Ekpoma, Edo State, Nigeria. Two methods were used in this study such as the Electrical Resistivity approach involving the use of Lateral Horizontal Profiling (LHP), 2D Electrical Resistivity Tomography (ERT), and Vertical Electrical Sounding (VES) techniques. While geotechnical method involved the collection of soil samples from the study locations for the characterization of the soil properties that are very vital to foundation studies. Nine VES were carried out using Schlumberger array with current electrode spacing varying from 1 to 40 m, with 2-D ERT using Dipole-Dipole electrode array with inter-station separation of 5 m and an expansion factor varied from 1 to 5 while LHP involve Wenner array with an electrode spacing of 5 m interval and was used to determine the vulnerability factors for the building sustainability. The VES interpretation results were used to determine the second-order parameters for the determination of vulnerability. The results obtained from the two methods review that both are very fundamental to foundation dynamics. However, electrical attributes were found to give better information in terms of depth, lateral extent, layer stratification, and nature of materials which make it an indispensable tool over geotechnical attributes whose depth of investigation is up to a maximum of 5 m which poses great limitation in the evaluation of structural integrity, against stress, and strain occasion by geodynamic activities that often result into fracture, crack, highly weathered formation that usually goes beyond the shallow depth of investigation. Therefore, it can be stated that resistivity attributes account for 90% of the major contributing factors that affect foundation vulnerability.
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YUEN, Y. P., and J. S. KUANG. "MASONRY-INFILLED RC FRAMES SUBJECTED TO COMBINED IN-PLANE AND OUT-OF-PLANE LOADING." International Journal of Structural Stability and Dynamics 14, no. 02 (January 5, 2014): 1350066. http://dx.doi.org/10.1142/s0219455413500661.
Анотація:
The structural responses of infilled frames subjected to combined in-plane and out-of-plane loadings are usually analyzed by separately applying in-plane and out-of-plane loads. The interaction effect of in-plane and out-of-plane loads on the structural behavior of the frames is ignored; thus errors in predicting the actual force-transfer mechanisms and modes of failure of the structures can be incurred. To solve the problem, this paper presents a discrete finite element modeling technique, which employs a damage-based cohesive crack representation of fracture behavior of masonry infills, followed by a study on the force-transfer mechanisms and failure modes of the anchored and unanchored infilled reinforced concrete (RC) frames subjected to interactive in-plane and out-of-plane loads. The analysis indicates that under out-of-plane loading the diagonal compressive thrust of masonry-infill walls, which is induced by in-plane lateral loading and acts on the walls, may reduce the in-plane load capacity of the RC frame by up to 50% and cause buckling of infill walls. On the other hand, the anchorage can effectively prevent the separation of infill walls from the bounding frame and provide stabilizing forces to the walls against buckling.
26
Bendall, Betina, Anne Forbes, and Tony Hill. "Resolving lithostratigraphic complexities in the Crayfish Group, Otway Basin using chemostratigraphy." APPEA Journal 61, no. 2 (2021): 588. http://dx.doi.org/10.1071/aj20114.
Анотація:
The Otway Basin comprises a significant part of the eastern Australian Southern Rift System, a divergent passive continental margin formed during the Cretaceous separation of the Australian and Antarctic continents. Early rifting activity resulted in the development of many half grabens within the Otway Basin, which are largely infilled by sediments of the Casterton Formation and Crayfish Group. Despite over 20 years of exploration and hydrocarbon production from these units however, their lithostratigraphic characterisation and nomenclature remain ambiguous, with structural complexity and prevalent lateral facies changes leading to confusion in their basin-wide correlation. Deposited in a largely non-marine, fluvial/lacustrine environment, repeating cycles of sandstones and shales of the Crayfish Group can be difficult to resolve using petrology, palynology and wireline log data. The use of chemostratigraphy is favoured as an investigative tool in this situation since changes in provenance, lithic composition, facies, weathering and diagenesis are reflected in the mineralogy of the sediments, resulting in variations in their inorganic geochemistry. Uniform sedimentary successions can thus potentially be differentiated into unique sequences and packages based on their characteristic geochemistry, aiding in the resolution of complex structural relationships and facies changes. In this study, we present new inorganic geochemistry data for four key wells in the South Australian (SA) Penola Trough and interpret the geochemistry data consistent with, and building on, the chemostratigraphic schema of Forbes et al. to demonstrate its utility and robustness. We then undertake inter-well wireline log correlations across the SA Penola Trough using the wells with chemostratigraphic data as controls.
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Bentley, Kevin J., and M. Hesham El Naggar. "Numerical analysis of kinematic response of single piles." Canadian Geotechnical Journal 37, no. 6 (December 1, 2000): 1368–82. http://dx.doi.org/10.1139/t00-066.
Анотація:
Recent destructive earthquakes have highlighted the need for increased research into the revamping of design codes and building regulations to prevent further catastrophic losses in terms of human life and economic assets. The present study investigated the response of single piles to kinematic seismic loading using the three-dimensional finite element program ANSYS. The objectives of this study were (i) to develop a finite element model that can accurately model the kinematic soilstructure interaction of piles, accounting for the nonlinear behaviour of the soil, discontinuity conditions at the pilesoil interface, energy dissipation, and wave propagation; and (ii) to use the developed model to evaluate the kinematic interaction effects on the pile response with respect to the input ground motion. The static performance of the model was verified against exact available solutions for benchmark problems including piles in elastic and elastoplastic soils. The geostatic stresses were accounted for and radiating boundaries were provided to replicate actual field conditions. Earthquake excitation with a low predominant frequency was applied as an accelerationtime history at the base bedrock of the finite element mesh. To evaluate the effects of the kinematic loading, the responses of both the free-field soil (with no piles) and the pile head were compared. It was found that the effect of the response of piles in elastic soil was slightly amplified in terms of accelerations and Fourier amplitudes. However, for elastoplastic soil with separation allowed, the pile head response closely resembled the free-field response to the low-frequency seismic excitation and the range of pile and soil parameters considered in this study.Key words: numerical modelling, dynamic, lateral, piles, kinematic, seismic.
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Walker, James T., and Paul J. McDermott. "Confirming the Presence of Legionella pneumophila in Your Water System: A Review of Current Legionella Testing Methods." Journal of AOAC INTERNATIONAL 104, no. 4 (January 23, 2021): 1135–47. http://dx.doi.org/10.1093/jaoacint/qsab003.
Анотація:
Abstract Legionnaires’ disease has been recognized since 1976 and Legionella pneumophila still accounts for more than 95% of cases. Approaches in countries, including France, suggest that focusing risk reduction specifically on L. pneumophila is an effective strategy, as detecting L. pneumophila has advantages over targeting multiple species of Legionella. In terms of assays, the historically accepted plate culture method takes 10 days for confirmed Legionella spp. results, has variabilities which affect trending and comparisons, requires highly trained personnel to identify colonies on a plate in specialist laboratories, and does not recover viable-but-non-culturable bacteria. PCR is sensitive, specific, provides results in less than 24 h, and determines the presence/absence of Legionella spp. and/or L. pneumophila DNA. Whilst specialist personnel and laboratories are generally required, there are now on-site PCR options, but there is no agreement on comparing genome units to colony forming units and action limits. Immunomagnetic separation assays are culture-independent, detect multiple Legionella species, and results are available in 24 h, with automated processing options. Field-use lateral flow devices provide presence/absence determination of L. pneumophila serogroup 1 where sufficient cells are present, but testing potable waters is problematic. Liquid culture most probable number (MPN) assays provide confirmed L. pneumophila results in 7 days that are equivalent to or exceed plate culture, are robust and reproducible, and can be performed in a variety of laboratory settings. MPN isolates can be obtained for epidemiological investigations. This accessible, non-technical review will be of particular interest to building owners, operators, risk managers, and water safety groups and will enable them to make informed decisions to reduce the risk of L. pneumophila.
29
Cogurcu, M. T. "Construction and design defects in the residential buildings and observed earthquake damage types in Turkey." Natural Hazards and Earth System Sciences 15, no. 4 (April 30, 2015): 931–45. http://dx.doi.org/10.5194/nhess-15-931-2015.
Анотація:
Abstract. Turkey is situated in a very active earthquake region. In the last century, several earthquakes resulted in thousands of deaths and enormous economic losses. In 1999, the Kocaeli earthquake had an approximate death toll of more than 20 000, and in 2011 the Van earthquake killed 604 people. In general, Turkish residential buildings have reinforced concrete structural systems. These reinforced concrete structures have several deficiencies, such as low concrete quality, non-seismic steel detailing and inappropriate structural systems including several architectural irregularities. In this study, the general characteristics of Turkish building stock and the deficiencies observed in structural systems are explained, and illustrative figures are given with reference to the Turkish Earthquake Code 2007. The poor concrete quality, lack of lateral or transverse reinforcement in beam–column joints and column confinement zones, high stirrup spacings, under-reinforced columns and over-reinforced beams are the primary causes of failures. Other deficiencies include weak-column–stronger-beam formations, insufficient seismic joint separations, soft-story or weak-story irregularities and short columns. Similar construction and design mistakes are also observed in other countries situated on active earthquake belts. Existing buildings still have these undesirable characteristics, and so to prepare for future earthquakes they must be rehabilitated.
30
Tolga Çöğürcü, M. "Building and design defects observed in the residential sector and the types of damage observed in recent earthquakes in Turkey." Natural Hazards and Earth System Sciences Discussions 3, no. 1 (January 22, 2015): 697–760. http://dx.doi.org/10.5194/nhessd-3-697-2015.
Анотація:
Abstract. Turkey is situated in a very active earthquake region. In the last century, several earthquakes resulted in thousands of deaths and enormous economic losses. In 1999, the Marmara earthquake had an approximate death toll of more than 20 000, and in 2011, the Van earthquake killed 604 people. In general, Turkish residential buildings have reinforced concrete structural systems. These reinforced concrete structures have several deficiencies, such as low concrete quality, non-seismic steel detailing, and inappropriate structural systems including several architectural irregularities. In this study, the general characteristics of Turkish building stock and the deficiencies observed in structural systems are explained, and illustrative figures are given with reference to Turkish Earthquake Code 2007 (TEC, 2007). The poor concrete quality, lack of lateral or transverse reinforcement in beam-column joints and column confinement zones, high stirrup spacings, under-reinforced columns and over-reinforced beams are the primary causes of failures. Other deficiencies include weak column-stronger beam formations, insufficient seismic joint separations, soft story or weak story irregularities and short columns. Similar construction and design mistakes are also observed in other countries situated on active earthquake belts. Existing buildings still have these undesirable characteristics, so to prepare for future earthquakes, they must be rehabilitated.
31
Boda, Zoltan, Miklos Udvardy, Katalin Razso, Mariann Szarvas, Katalin Farkas, Judit Toth, Laszlo Jambor, et al. "Autologous Bone Marrow-Derived Stem Cell Therapy in Patients with Severe Peripheral Arterial Disorders: A Pilot Study." Blood 110, no. 11 (November 16, 2007): 2877. http://dx.doi.org/10.1182/blood.v110.11.2877.2877.
Анотація:
Abstract Introduction. Amputation is the only current option for relief of rest pain or gangrene in patients with severe peripheral arterial disease (SPAD). Up to now, no effective blood-flow enhancement therapies are available. Autologous bone marrow-derived stem cell transplantation (ABMSCT) is an arising therapy modality with an option of building new blood vessels through endothelial stem and/or progenitor cells. Methods. Five patients with SPAD (4 with Buerger’s disease and 1 with arteriosclerosis obliterans) were treated by ABMSCT. CD34+/CD133+ cell counts were determined in aspirated bone marrow, CD34+ cells were isolated by magnetic separation and collected into a 10 ml sample. The stem cell suspension was administered by local intramuscular injections (0.5–1.0 ml injections in the musculus gastrocnemius). The follow-up (before; 1−, 3− and 6 months after ABMSCT) based on clinical (rest pain, walking distance without pain, changes of non-healing ulcers, ABI) and laboratory (DS-angiography, Color- and Laser-Doppler scan, TcPO2 measurement and endothel function test) parameters was documented and analyzed. Our goal was to treat the worse limb of all the 5 patients. Results. Therapeutic benefit was shown by complete regression of rest pain in all 5 patients, and by the significant increase of pain-free walking distance (36 m vs. 440 m). Six months after ABMSCT the ischemic ulcers disappeared in 2 patients, and in another 2 patients the large and deep ulcers became smaller and thinner (from 8 cm2 to 2.6 cm2 in one case, and from 30 cm2 to 8 cm2 in another case), and in 1 case no change was realized, where osteomyelitis of the affected toe was diagnosed. The average of ABI improved significantly on the treated lower limb (before: 0.41, 3 and 6 months after: 0.64/0.82). ABI values of the contra-lateral legs did not change. The clinical improvement started 1 months after ABMSCT, it became more prominent after 3 months, and the best clinical results were observed after 6 months of transplantation. Confirmed by post-trial observations obtained at 9 months the clinical improvement was evaluated as stable and long lasting. Using angiography we realized improvement in 3 cases, but only in 1 case using Color-Doppler scan. Before and 6/20 weeks after transplantation the TcPO2 changed on the foot from 18.80/16.78/23.83 mmHg, and on the calf from 36.66/31.25/45.00 mmHg. The laboratory parameters did not show improvement after 1 month, however, after 3 and 6 months improved parameters were recorded. No severe complications, adverse events were detected during the 6 months follow-up period. Conclusions. ABMSCT with isolated CD34+ cells was proved to be safe, effective and resulted in significant and sustained improvement of clinical parameters and quality of life for patients with SPAD. Multicentric, controlled clinical trials are required to confirm these preliminary clinical results.
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Khatami, Mostafa, Mohsen Gerami, Ali Kheyroddin, and Navid Siahpolo. "The Effect of the Mainshock–Aftershock on the Estimation of the Separation Gap of Regular and Irregular Adjacent Structures with the Soft Story." Journal of Earthquake and Tsunami 14, no. 02 (December 6, 2019): 2050008. http://dx.doi.org/10.1142/s1793431120500086.
Анотація:
One way for decreasing the effect of pounding is to set the separation gap between two adjacent buildings. On the one hand, earthquakes in earthquake-prone zones often occur as a chain of successive earth movements in the form of foreshock, mainshock and aftershock. On the other hand, the existence of soft story in the lowest story of the structure is the most common type of irregularity in lateral stiffness. This paper investigates the effect of seismic sequences to estimate the separation gap at the highest collision level of two adjacent structures. For this purpose, 335 adjacent combinations of regular and irregular steel moment-resisting frames are evaluated which have a soft story on the first story. Separation gap demand is calculated using dynamic analysis of nonlinear time history under a set of seismic sequences which are a combination of the mainshock and aftershock. Results of the total of analysis done show the seismic sequence effects are significant and should be considered in the process of determining the normal separation gap (here after, NSG). Finally, based on the done studies, an empirical relationship is presented to estimate the seismic sequence effects on separation gap of two regular and irregular adjacent structures.
33
Wu, Di, Yoshihiro Yamazaki, and Hiroyasu Sakata. "Dual Equivalent Lateral Force Method for Low-Rise Wooden Horizontal Hybrid Structure with Rigid Core." Shock and Vibration 2018 (December 17, 2018): 1–8. http://dx.doi.org/10.1155/2018/1940706.
Анотація:
Hybrid structure has shown some great features in the earthquake-resistant design. However, due to the different properties between the combined building systems, the distributions of structural mass and stiffness are prevalently irregular in breadth or height, which makes the widely used equivalent lateral force (ELF) method powerless to predict the seismic shear force of such hybrid structure. This study proposed a simple design procedure for determining the concerned seismic shear force of low-rise wooden horizontal hybrid structure in the preliminary linear design. The dual equivalent lateral force (DELF) method is presented that permits the extension of the ELF method by separating the hybrid structure into two independent substructures. It is shown that the proposed DELF method is sufficient to provide a reasonable estimation of the seismic shear force with satisfied accuracy.
34
Magrini, Anna, and Lorenza Magnani. "Models of the Influence of Coupled Spaces in Christian Churches." Building Acoustics 12, no. 2 (June 2005): 115–39. http://dx.doi.org/10.1260/1351010054037956.
Анотація:
Ancient religious buildings usually contain articulated environments, such as lateral chapels, in which the effect of multiple acoustically coupled spaces can influence the sound field in the central volume. By introducing absorbent materials in a lateral chapel, the acoustic response of the whole church can be altered. If the effects of coupled spaces are described by geometrical acoustics, inaccurate results may be obtained since reverberation time is influenced by mutual power interactions through the coupling areas or separating walls. Two methods are considered, to determine the simplest way to obtain accurate values of reverberation time for these situations. The results of the simulations are compared with experimental values and indicate areas of applicability of the tested methods.
35
Behrens, R. A., and T. T. Tran. "Incorporating Seismic Data of Intermediate Vertical Resolution Into Three-Dimensional Reservoir Models: A New Method." SPE Reservoir Evaluation & Engineering 2, no. 04 (August 1, 1999): 325–33. http://dx.doi.org/10.2118/57481-pa.
Анотація:
Summary Three-dimensional (3D) earth models are best created with a combination of well logs and seismic data. Seismic data have good lateral resolution but poor vertical resolution compared to wells. The seismic resolution depends on seismic acquisition and reservoir parameters, and is incorporated into the 3D earth model with different techniques depending on this resolution relative to that of the 3D model. Good vertical resolution of the seismic data may warrant integrating it as a continuous vertical variable informing local reservoir properties, whereas poor resolution warrants using only a single map representing vertically averaged reservoir properties. The first case best applies to thick reservoirs and/or high-frequency seismic data in soft rock and is usually handled using a cokriging-type approach. The second case represents the low end of the seismic resolution spectrum, where the seismic map can now be treated by methods such as block kriging, simulated annealing, or Bayesian techniques. We introduce a new multiple map Bayesian technique with variable weights for the important middle ground where a single seismic map cannot effectively represent the entire reservoir. This new technique extends a previous Bayesian technique by incorporating multiple seismic property maps and also allowing vertically varying weighting functions for each map. This vertical weighting flexibility is physically important because the seismic maps represent reflected wave averages from rock property contrasts such as at the top and base of the reservoir. Depending on the seismic acquisition and reservoir properties, the seismic maps are physically represented by simple but nonconstant weights in the new 3D earth modeling technique. Two field examples are shown where two seismic maps are incorporated in each 3D earth model. The benefit of using multiple maps is illustrated with the geostatistical concept of probability of exceedance. Finally, a postmortem is presented showing well path trajectories of a successful and unsuccessful horizontal well that are explained by model results based on data existing before the wells were drilled. Introduction Three-dimensional (3D) earth models are greatly improved by including seismic data because of the good lateral coverage compared with well data alone. The vertical resolution of seismic data is poor compared with well data, but it may be high or low compared with the reservoir thickness as depicted in Fig. 1. Seismic resolution is typically considered to be one-fourth of a wavelength (?/4) although zones of thinner rock property contrasts can be detected. The seismic resolution relative to the reservoir thickness constrains the applicability of different geostatistical techniques for building the 3D earth model. Fig. 1 is highly schematic and not meant to portray seismic data as a monochromatic (single-frequency) wave. The reference to wavelength here is based on the dominant frequency in the seismic data. Fig. 1 is meant to illustrate the various regimes of vertical resolution in seismic data relative to the reservoir thickness. While there are all sorts of issues, such as tuning, that must be considered in the left two cases, we need to address these cases because of their importance. Seismic data having little vertical resolution over the reservoir interval, as in the left case of Fig. 1 can use geostatistical techniques that incorporate one seismic attribute map. The single attribute can be a static combination of multiple attributes in a multivariate sense but the combination cannot vary spatially. These techniques include sequential Gaussian simulation with Block Kriging1 (SGSBK), simulated annealing,2 or sequential Gaussian simulation with Bayesian updating.3,4 Some of these methods are extendable beyond a single seismic map with modification. Seismic data having good vertical resolution over the reservoir interval, as in the right seismic trace of Fig. 1, can use geostatistical techniques that incorporate 3D volumes of seismic attributes. Techniques include simulated annealing, collocated cokriging simulation,5 a Markov-Bayes approach,6 and spectral separation. The term "3D volume" of seismic, as used here, is distinguished from the term "3D seismic data." (A geophysicist speaks of 3D seismic data when it is acquired over the surface in areal swaths or patches for the purpose of imaging a 3D volume of the earth. Two-dimensional (2D) seismic is acquired along a line on the surface for the purpose of imaging a 2D cross section of the earth.) The 3D volume distinction is made based on the vertical resolution of the seismic relative to the reservoir. To be considered a 3D volume here, we require both lateral and vertical resolution within the reservoir. Seismic data often do not have the vertical resolution within the reservoir zone to warrant using a 3D volume of seismic data. The low and high limits of vertical resolution leave out the case of intermediate vertical resolution as depicted by the middle curve of Fig. 1. Because typical seismic resolution often ranges from 10 to 40 m and many reservoirs have thicknesses one to two times this range, many reservoirs fall into this middle ground. These reservoirs have higher vertical seismic resolution than a single map captures, but not enough to warrant using a 3D volume of seismic. It is this important middle ground that is addressed by a new technique presented in this paper.
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Hiwase, Prashant, Vipul V. Taywade, and Sharda P. Siddh. "Comparative analysis of vertical irregularities on high rise structure considering various parameters." IOP Conference Series: Materials Science and Engineering 1197, no. 1 (November 1, 2021): 012024. http://dx.doi.org/10.1088/1757-899x/1197/1/012024.
Анотація:
Abstract Now, every day tall constructing structures constructed around the goal of residential and industrial cause etc. Layout of tall buildings both earthquake as well as wind loads got to be take into considered. An irregular structure, failure of structure starts at a point of its weakness and those weaknesses comesups withs separation of mass, stiffness and geometry of that models. The structures having this kinds of discontinuity are called Irregular structures. (H, J, & darshan, 2017) [2]. For example,Structures with the soft storey were the foremost remarkable fallen structures. Therefore, the impact of vertical alignment within the seismic structure of buildings is very significant. The changes in durability and size provide powerful features of those structures that are completely different from the standard structure. For this present evaluation ‘ETABS’ software package is employed. All Reinforced Concrete structural elements are follows as per ‘IS 456:2000 (Plane and Reinforce Concrete-Code of Practice, Bureau of Indian Standard)’. Seismic load follows with respect to IS 1893:2016 along with self-weight of modelles for analysis of the structure. Here 2 kinds of buildings of (G+15) were created one is regular structure and alternative one Mass irregular. To observe, Effect of lateral in both buildings using Seismic load and to check the results,most of maximum displacement for various models and various parameters.
37
Shendkar, Mangeshkumar R., Denise-Penelope N. Kontoni, Ercan Işık, Sasankasekhar Mandal, Pabitra Ranjan Maiti, and Ehsan Harirchian. "Influence of Masonry Infill on Seismic Design Factors of Reinforced-Concrete Buildings." Shock and Vibration 2022 (February 27, 2022): 1–15. http://dx.doi.org/10.1155/2022/5521162.
Анотація:
Infill walls are the most common separator panels in typical reinforced-concrete (RC) frame structures. It is crucial to investigate the influence of the infill walls on the earthquake behavior of RC frames. The load resistance of infill materials was often not taken into account in the designing phase, whereas the infill walls have significant contributions to the structural behavior under lateral and vertical loadings. A three-dimensional 4-story RC building is designed, and in order to make a realistic model, different infill walls configurations were taken into account with the openings in the infill. Four different models were created for structural analysis for infill wall effects, namely, full RC infilled frame (Model I), corner infill at ground story RC infilled frame (Model II), open ground story RC infilled frame (Model III), and bare RC frame (Model IV). Static adaptive pushover analysis has been performed for all structural models by using the SeismoStruct software. The double strut nonlinear cyclic model was used for modeling the infill walls. In this study, three different compressive strengths of infill walls are taken into consideration, and the effects on seismic design factors (namely, the response reduction factor, the ductility, the overstrength factor, and the deflection factor) are calculated. The obtained values of the response reduction factor (R) are compared with the given values in the BIS code. The results show that the R factors of all RC infilled frames are decreased when the compressive strength of the masonry infill reduces. However, the R values of bare frames are less than the corresponding values recommended in the BIS code. It is worth noting that the National Earthquake Hazards Reduction Program (NEHRP) provisions underestimate the deflection factors of the reinforced-concrete (RC) frames according to the evaluated deflection factors of the herein studied RC frames.
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Susila, Gede Adi, Parthasarati Mandal, and Thomas Swailes. "Strengthening and Retrofitting Strategy for Masonry (New Build Construction in Indonesia)." Applied Mechanics and Materials 845 (July 2016): 181–87. http://dx.doi.org/10.4028/www.scientific.net/amm.845.181.
Анотація:
In Indonesia, number of non-engineered structures have significantly been found which the houses were built by unskilled workers using masonry either unconfined or confined. The non-engineered housing units developed in urban region are also vulnerable to seismic hazard due to the use of low quality of material and constructions method. Those structures are not resistant to extreme lateral loads and their failure during an earthquake can lead to significant loss of life. This paper is concerned with the structural performance of Indonesian low-rise buildings made of masonry under lateral seismic load. Experimental testing of masonry has been carried out in Indonesia to establish the quality of materials and to provide material properties for numerical simulations. The results found that the strength of Indonesia-Bali clay brick masonry are below the minimum standard required for masonry structures built in seismic regions, being at least 50% lower than the requirement specified in British Standard and Eurocode-6 (BS EN 1996-1-1:2005). In general, structural tests under monotonic and cyclic loading have been conducted to determine the load-displacement capacity of local hand-made masonry wall panels in order to: (1) evaluate the performance of masonry structure, (2) investigate the dynamic behaviour of the structure, and (3) observe the effect of in-plane stiffness and ductility level. Detailed numerical models of the experimental specimens were simulated in Abaqus using three-dimensional solid elements. Cohesive elements were used to simulate the mortar behaviour, exhibiting cracking and the associated physical separation of the elements. A range of available material plasticity models were reviewed: Drucker-Prager, Crystalline Plasticity, and Cohesive Damage model. It was found that the combination of Crystalline Plasticity model for the brick unit and the Cohesive Damage model for the mortar is capable of simulating the experimental load-displacement behavour fairly accurately. The validated numerical models have been used to (1) predict the lateral load capacity, (2) determine the cracking load and patterns, (3) carry out a detailed parametric study by changing the geometric and material properties different to the experimental specimens. The numerical models were used to assess different strengthening measures such as using bamboo as reinforcement in the masonry walls which the performance of wall found to be better
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Naderpour, Hosein, Seyed Mohammad Khatami, and Rui Carneiro Barros. "Prediction of Critical Distance Between Two MDOF Systems Subjected to Seismic Excitation in Terms of Artificial Neural Networks." Periodica Polytechnica Civil Engineering, January 31, 2017. http://dx.doi.org/10.3311/ppci.9618.
Анотація:
This study focuses on preventing collisions between structuresduring seismic excitation based on gap size. Several approximatedequations in order to estimate separation distancebetween buildings are collected and evaluated to measure gapsize in order to avoid impact between them when large lateraldisplacements occurred due to earthquake. Artificial neuralnetworks are utilized to estimate the required distance betweenstructures. The majority of building codes suggest separationdistances based on maximum lateral displacements of eachbuilding or height of buildings in order to provide safety gapsize between them. Subsequently, researchers have proposedseveral equations to predict the critical distance. In currentstudy, some MDOF models are equivalently modelled and optimumgap size between buildings is approximately estimatedand finally a new equation for separation distance is suggestedand the accuracy of formula is numerically investigated.
40
Rios Mora, Juan Sebastian, Thierno Diallo, Bernard Collignan, Marc Abadie, and Karim Limam. "Vapor intrusion in buildings: Development of semi-empirical models including lateral separation between the building and the pollution source." Building Simulation, June 1, 2022. http://dx.doi.org/10.1007/s12273-022-0910-3.
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Meng, Xun, Ding Zhou, and Jiadong Wang. "Effect of Vertical Elastic Baffle on Liquid Sloshing in Rectangular Rigid Container." International Journal of Structural Stability and Dynamics, August 23, 2021, 2150167. http://dx.doi.org/10.1142/s0219455421501674.
Анотація:
Sloshing may induce adverse loads to cause structural instability and damage. A vertical elastic baffle mounted at the inside bottom of a rectangular container is used as an anti-slosh device to attenuate the liquid oscillation. A semi-analytical model is presented to analyze the hydroelastic problem. The liquid is partitioned into four simple sub-domains with three hypothetical interfaces. The velocity potential of each sub-domain is analytically deduced by the separation of variables. The baffle deflection is expanded into the Fourier series by its dry modals. The eigenvalue equation is formulated by plugging the velocity potentials into the sloshing conditions, interface continuity conditions, as well as the dominant equation and compatibility conditions of the baffle. Then, the velocity potential is expressed by a complete basis of the coupled mode shapes for the system considered under lateral excitation. The system response equation is constituted by inserting the velocity potential into wave equations and baffle equation. The proposed method is verified by comparing the present results with the available data. In addition, numerical analyses are performed to examine the effects of baffle parameters on the natural frequencies, mode shapes and dynamic responses of the container. The sloshing frequency may be altered to a higher value due to the installation of the elastic baffle.
42
Melcher, Daniel J. "Forensic Engineering Analysisf A Truck Accident." Journal of the National Academy of Forensic Engineers 28, no. 1 (January 1, 2011). http://dx.doi.org/10.51501/jotnafe.v28i1.742.
Анотація:
Forensic Engineering Analyses Of Collision Events Often Focus On Physics Models And Calculation Methods Governing The Forces Occurring During An Impact And After The Separation Of The Vehicles. However, Physics Models And Calculation Methods Governing The Motion Of Vehicles In Normal Linearnd Rotational Dynamics, Outside Of The Impact Phase, Can Be Applied To A Forensic Engineering Analysis To Gain Insight Into The Collision Events. Techniques From The Fields Of Automotive Engineering And Highway Engineering, When Applied By The Forensic Engineer, Can Answer Critical Questions About Aarticular Case, Or May Be Able To Eliminate Hypothetical Scenarios Proposed By Others. He Mechanical Systems And Dynamics Of Commercial Vehicles, Especially Articulated Vehicles, Differreatly From The Dynamics Of Typical Utomobiles. The Limitations And Performance Capabilities Ofommercial Vehicles In Acceleration, Lateral Motion, Rotational Yaw, Roll And Pitch, And Handling Characteristicsan Be Used To Analyze Events Leading Up To A Collision Or To Evaluate Avoidance Capabilities. Annderstanding Of Factors Such As Articulation, High Enters Of Gravity, Rollover Propensity, Off-Tracking Inurns, Jack-Knifes, Trailer Swingouts, Acceleration Rates, And Lane Change Performance Is Essential In Thenvestigation And Reconstruction Of Commercial Vehicle Collisions. This Paper Will Provide An Introductiono Vehicle Dynamics Concepts Applicable To Commercial Vehicle Collisions, With A Combination Ofcientific Theories That Are Unique To Heavy Vehicles.
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O. Ilugbo, S., A. D. Adebiyi, S. O. Olaogun, and T. Egunjobi. "Application of Electrical Resistivity Method in Site Characterization along Ado – Afao Road, Southwestern Nigeria." Journal of Engineering Research and Reports, July 20, 2018, 1–16. http://dx.doi.org/10.9734/jerr/2018/v1i49871.
Анотація:
A geophysical study was carried out at a proposed location for the construction of a structure along Ado-Afao road, Southwestern Nigeria. The aim of the study is to evaluate the electrical properties of the soil for Founding of Engineering structures. The geophysical investigation involved the Vertical Electrical Sounding (VES) technique using the Schlumberger configuration with a total of twenty-one (21) VES within the investigated area. The electrode separation varies from 1 to 100 m. The geoelectric sections identified three to five geoelectric/geologic subsurface layers along the traverses. The topsoil comprising of clay, clayey sand and sandy clay with the resistivity values range from 28 to 800 Ω-m with its thickness varying from 0.4 to 1.9 m. The second layer was found to be lateritic with resistivity ranging between 200 to 800 Ω-m and thickness ranges from 1 to 7.5 m while the weathered layer comprising of clay, clayey sand and sandy clay with resistivity varies from 30 to 220 Ω-m and its thickness varies from 1.2 to 54 m. The fractured basement with resistivity value of 763 Ωm and thickness value of 8m while the fresh basement has a resistivity value ranging from 365 to 2964 Ωm with depth to basement ranging from 8 to 58 m. The resistivity values of the topsoil are indicative of clay, sandy clay and clayey sand. This layer may not be of any special interest since topsoil is normally excavated. Hence, foundation of the proposed structures cannot be found on this layer. Based on the investigation, the subsurface of the study area can be generally classified as incompetent. There is a presence of lateral inhomogeneity of the subsurface layers and geologic features such as fractures and faults. The construction in the area should be founded on the lateritic layer or fresh basement layer coupled with pile foundation to ensure the stability of the building. The choice of foundation material, clay content and topography elevation should be put into consideration.